The present disclosure relates generally to wellbore operations and, more particularly, to systems and methods for remote actuation of a downhole tool.
Hydrocarbon-producing wells are often stimulated by hydraulic fracturing operations in order to enhance the production of hydrocarbons present in subterranean formations. During a typical fracturing operation, a servicing fluid (i.e., a fracturing fluid or a perforating fluid) may be injected into a subterranean formation penetrated by a wellbore at a hydraulic pressure sufficient to create or enhance fractures within the subterranean formation. The resulting fractures serve to increase the conductivity potential for extracting hydrocarbons from the subterranean formation.
In some wellbores, it may be desirable to selectively generate multiple fractures along the wellbore at predetermined distances apart from each other, thereby creating multiple “pay zones” in the subterranean formation. Some pay zones may extend a substantial distance along the axial length of the wellbore. In order to adequately fracture the subterranean formation encompassing such zones, it may be advantageous to introduce a stimulation fluid via multiple stimulation assemblies arranged within the wellbore at spaced apart locations on a work string extended therein. Each stimulation assembly may include, for example, a sliding sleeve configured to be opened and shut in order to allow fluid communication between the interior of the work string and the surrounding subterranean formation.
In some applications, the sleeve may be opened or otherwise actuated by introducing a ball or dart into the work string which engages an internal baffle or seat defined on the interior surface of the work string. Once the ball is properly seated on its corresponding internal baffle, the work string is pressurized and the increased pressure serves to actuate the sleeve via a variety of mechanical or hydraulic means. While effective in opening the sleeve, the ball must be retrieved from the work string or otherwise drilled out in order to introduce other downhole tools or assemblies past that point in the work string. Moreover, the interior baffles that seat the ball necessarily reduce the inner diameter of the work string, thereby reducing the size of tools and devices that may be extended past that point in the work string.
In other applications, the sleeve may be actuated using one or more downhole electromechanical or hydromechanical devices configured to receive a command signal from the surface when actuation is required. Providing command signals to downhole electronic equipment, however, can be problematic for a number of reasons. Electrical signal wires running down the wellbore may become cut by abrasion or twisted and broken during run-in. Also, the ambient downhole environment may interfere with reception of acoustic or electromagnetic signals sent from the surface and, in addition, signal attenuation for a deep well may reduce the strength of an acoustic signal below a reception threshold of the equipment even in the absence of interference.
While there are several methods of actuating downhole tools, such as sliding sleeve assemblies, it nonetheless remains advantageous to find new and improved methods of actuating downhole tools that will reduce costs and increase hydrocarbon extraction efficiency.